The present invention relates to a cooling device for a hybrid vehicle, comprising an internal combustion engine coupled to an electrical machine, and a device for storing electrical energy, such as a battery. The cooling of the different electrical components, the electrical energy storage device, and the combustion engine is ensured by a heat transfer fluid circulating through thermal heat exchangers. The invention also relates to a radiator for installation in a hybrid vehicle.
For clarity purposes, the electrical energy storage device will be referred to in the specification simply by the term “battery”. However, the storage device can include, for example, several batteries and/or several super capacitors. A hybrid vehicle normally uses a supplementary battery dedicated to supplying electricity to the electric motor. The storage capacity is much larger than that of the normal battery. As a result, the battery has a tendency to heat up because it is used more than in a vehicle with only a combustion engine. The battery operates optimally in a well-defined temperature range, generally about 40° C. However, cooling is necessary to maintain a temperature of about 40° C. For this purpose, cooling with air, a heat transfer fluid, or a coolant can be used. In the case of a heat transfer fluid or coolant, a cooling circuit is used having a heat exchanger, such as a radiator, for circulation of the heat transfer fluid or coolant.
Other electrical components of the vehicle also need to be cooled, such as the electrical traction motor(s) or the inverter, to operate in an optimal temperature range, generally about 60° C. Another cooling circuit having a heat exchanger is used for this purpose.
Similarly, the combustion engine needs to be cooled for operation in a typical temperature range, generally about 80° C. Another cooling circuit having a heat exchanger is used for this purpose.
In general, three cooling circuits having three heat exchangers are used with each cooling circuit operating in a different temperature range. While this configuration optimizes the cooling, it requires the addition of heat exchangers and the creation of independent cooling circuits. Therefore, it would be very advantageous to reduce the number of heat exchangers and, generally, to modify the cooling circuits for reduction of the cost and the space occupied under the hood of the vehicle.
Vehicles equipped with climate control can also use the cooling fluid of the climate control circuit. However, as discussed above, such a configuration requires a dedicated cooling circuit. In addition, this configuration generates higher energy consumption due to the operation of a climate control compressor.
FIG. 1 illustrates the most widely used prior art configuration using independent cooling circuits for circulation of a heat transfer fluid, which demonstrates the disadvantages of the prior art.